Actually you probably have a Chrysler 9 1/4 rear end. It was introduced around 69/70 and Chrysler used it to replace both the 8 3/4 and the Dana.
It is completly different than either the Dana or 8 3/4. As I recall it has a 12 bolt rear cover. They are a pretty good unit and supported reasonably well in the aftermarket. I've found a pretty fair amount of them with Posi's both in passenger cars and light trucks.